1. Field of the Invention
The present invention relates to a convection fan control method of a microwave oven, in particular to a convention fan control method of microwave oven which is capable of altering discharge direction of the air heated by a heater to a heating object by controlling the rotation direction of a convection fan in accordance with type of dish.
2. Description of the Prior Art
The general microwave oven heats a heating object (food) by using microwave generated from a magnetron.
Recently, besides the magnetron, other heating method is added to the microwave oven in order to provide various functions.
Among them, there is a method which heats the heating object by installing an additional heater and using the heat generated from the additional heater.
As depicted in FIG. 1, in a microwave oven comprising the heater as an additional heating source, a heater chamber 4 including heaters 6a, 6b is formed on the upper portion of a cavity 2 where the heating object is placed and is heated.
A fan 10 is installed on the inner middle portion of the heater chamber 4, the heaters 6a, 6b are installed on the both sides of the fan 10, and a motor M1 for rotating the fan 10 is installed on the outer side of the heater chamber above the fan 10.
Each blade 7 is installed on the left/right side of the fan 10 in order to generate air flow when the fan 10 rotates.
And, an air inlet hole 8 is formed on the middle upper surface of the cavity 2 corresponding to the bottom surface of the heater chamber 4, and each air outlet hole 9 is formed on the both sides of the air inlet hole 8 in order to circulate the air generated by the fan.
In more detail, the air inlet hole is formed on the direct lower portion of the fan 10 in order to suck inner air of the cavity 2, and the air outlet hole 9 is formed on the lower outer circumference portion of the fan 10 in order to provide the air sucked through the air inlet hole to the inner side of the cavity 2 by rotating of the fan 10.
The air inlet hole 8 and air outlet hole 9 are a plurality of air holes.
Hereinafter, the operation of the conventional microwave oven will now be described, in the conventional microwave oven, in order to heat the inside of the cavity 2 by using the heaters 6a, 6b, a power is applied to the heaters 6a, 6b in order to generate the heat, and at the same time the motor M1 is operated in order to operate the fan 10.
According to the operation of the fan 10, the air flowed from the inside of the cavity 2 toward the fan 10 through the air inlet hole 8 is discharged through the air outlet hole 9. Herein, the heat generated from the heaters 6a, 6b inside of the heater chamber 4 is applied to the inside of the cavity 2 through the air.
However, the conventional convection heater type microwave oven has some problems.
First, the air heated by the heaters 6a, 6b circulates inside of the cavity 2 through the air inlet hole 8 and air outlet hole formed on the bottom surface of the heater chamber 4.
In more detail, the air flowing toward the fan 10 installed on the heater chamber 4 is transferred to a radius direction of the blade 7 by the centrifugal force caused by the rotating of the fan 10 while flowing along the blade 7.
Accordingly, the air flows to the fan 10 through the air inlet hole 8 according to a decrease of pressure on the direct lower portion of the fan 10, the air is heat-exchanged with the heat generated by the heater 2, and the air heats the inside of the cavity 2 by being discharged into the cavity 2 through the air outlet hole 9.
In other words, in the conventional convection heater type microwave oven, the air circulating the inside of the cavity 2 flows through the air inlet hole 8 and air outlet hole 9 formed on the upper surface of the cavity 2. Accordingly, the heated air can contact to the heating object only after being heat-exchanged with the inner wall surface and the inner side surface area of the cavity 2.
Accordingly, it is not efficient to cook the heating object because the cooking temperature and cooking speed of the heating object are lowered.
The object of the present invention is to provide a convection fan control method of a microwave oven, in particular to a convention fan control method of a microwave oven which is capable of altering the discharge direction of the air heated by a heater to a heating object by controlling the rotation direction of a convection fan in accordance with the type of a dish.
In order to achieve above-mentioned problems, the convention fan control method of the microwave oven according to the present invention comprises a cooking time setting process for selecting a dish type of a heating object and setting cooking time, a rotation direction setting process for setting rotating direction of a fan motor which is capable of rotating and reverse-rotating, a fan motor operating process for operating the fan motor in accordance with the set rotating direction, a fan operating process for rotating a fan by the rotating of the fan motor, and a cooking process for cooking the heating object for the set cooking time by operating the heater.